Curtain rail



FIG. 1 is a front elevational view of a curtain rail showing new design, with the center broken away to indicate indeterminate length;

FIG. 2 is a top plan view thereof;

FIG. 3 is a side elevational view thereof, with the opposite side being a mirror image;

FIG. 4 is a perspective view thereof. 

The ornamental design for a curtain rail, as shown and described. 